“I study ants in the desert, in the tropical forest and in my kitchen,” says Deborah Gordon.

An ecologist, she researches the behavior of ant colonies — which are systems that operate without central control. (While they have a queen, Gordon explains, the queen only lays eggs and doesn’t actually issue orders.) Gordon thinks that, from ants, we can learn a lot about similar systems like the brain, data networks and even the growth of cancer cells.

Ants use their antennae to smell and interact. When they touch antennae with another ant, they receive quite a bit of information—including if an ant is from their colony and what task it’s been doing. “These interactions taken together produce a network,” says Gordon. “It’s this constantly shifting network that shapes the behavior of the colony.”

In other words, ants use interactions differently to meet the challenges of their environments. In the desert, for example, foraging for food—which contains in it water—has a high operating cost. “Ants have to spend water to get water,” says Gordon. In this environment, new foragers don’t go out to hunt for food unless they receive a certain number of positive interactions from foragers returning from the same task. “The system is set to stop unless interactions turn it positive,” says Gordon. It’s the same way the brain works—neurons add up stimulation from other neurons to determine whether to fire.

Different colonies set different thresholds for foraging. On dry days, some colonies conserve much more than others. Gordon was fascinated to find that offspring colonies — colonies founded by daughter queens — resemble their parent colonies in the algorithm they use to control foraging, even though they live far away and couldn’t have learned the behavior. Gordon was also surprised to find that the colonies that conserve are more likely to have offspring colonies. “I thought colony 154 was a loser,” she says, pointing to a colony that turns out to not only have offspring but grandchildren. “But colony 154 was in fact a huge success—a matriarch, one of the rare great-grandmothers. To my knowledge, this is the first time that we’ve been able to track the ongoing evolution of collective behavior.”

Interestingly, the way ants modulate foraging is remarkably similar to the algorithm the internet uses to control the flow of data. “Data doesn’t leave the source computer unless it gets the signal that there’s a place for it,” says Gordon. It was designed this way because, for so long, the cost of operation was high. “Ants are using a similar algorithm to one that we only recently invented,” says Gordon. “Ants have had 130 million years to evolve a lot of good ones. Some of the other 12,000 species have other interesting algorithms for data networks that we haven’t even thought of yet.”

Now, Gordon takes us to the tropics, where ant colonies face a different challenge—while there’s lots of food, there’s also lots of competition for it from other colonies. In these regions, “the system is set to go unless interactions turn it negative,” says Gordon. As ants wander and interact, they are sure to encounter ants from other colonies and, when this happens, the system pulls back. Gordon shows us a photo of an ant using its body to plug the hole to the colony when a threat was detected. “That could be useful for computer security—we could block access temporarily in response to a specific threat and then open it again when the threat’s passed instead of trying to build some kind of firewall.”

Ants also have a lot to teach us about a challenge in robotics—collective search. “Rather than sending a single, expensive robot out to explore another planet or search a burning building, it may be more effective to get a team of cheap robots sharing minimal info,” says Gordon. “That’s the way ants do it.” She explains how ants have mastered the art of expandable search networks. They’ve figured out how to use interactions to expand or contract their loops—when they are crowded and have a lot of interactions, they take tight paths and search them thoroughly. When they are sparse and meet infrequently, they trade off thoroughness to cover more territory. To gather data about how ants behave in crowded spaces, Gordon send a colony up in the International Space Station, where they are forced to cling to the walls, or ceiling, or whatever you call it, and compete for space in new ways. (She’s still analyzing the data that came back.)

So why do ants come marching across your picnic blanket, searching for your strawberries? Ants look for “clustered resources” and so, when an ant wanders upon a feast, it uses interactions to recruit other foragers to see if more is to be had. Hence, ants marching in a line.

Gordon wonders if this information could be helpful in treating cancer. Gordon explains that there are many types of cancer and that they develop in one area and metastasize in another area that has the resources it needs. “If those resources are clustered, they could be using interactions for recruitment,” says Gordon. “If we understood the way cancer cells used recruitment, maybe we could set traps to catch them before they become established.”

This is what we know now. And Gordon wonders what other ant wisdom may come from other colonies. She asks us all to observe and study ants.

“Using only simple interactions, ant colonies have been performing amazing feats for 130 million years,” she says. “We have a lot to learn from them.”

George Monbiot gets in touch with his rewilding side at TEDGlobal 2013. Photo: James Duncan Davidson

George Monbiot begins today’s talk by recalling a time he was “ecologically bored.”

“We evolved in rather more challenging times than these, in the world of horns and tusks and fangs and claws,” explains Monbiot, an investigative journalist who found himself deeply dissatisfied returning to the United Kingdom after years reporting in the tropics.
George Monbiot: For more wonder, rewild the world
“We still possess the fear and the courage and the aggression required to navigate those times. But in our comfortable, safe, crowded lands, we have few opportunities to exercise them without harming other people.”

In his search for a solution to this stupor, Monbiot discovered his current passion: rewilding.

It’s a term, coined by activist Dave Foreman and broadened by Michael Soulé and Reed Noss in the 1990s, that Monbiot explains has two meanings. The first involves the mass restoration of ecosystems through attention to “trophic cascades” — the ecological processes that start at the top of a food chain and tumble down to the bottom, affecting the entire ecosystem in the process. The second involves the rewilding of places humans live—restoring some of the fauna that we’ve wiped out through hunting and habitat destruction.

“Paleoecology—the study of past ecosystems crucial to an understanding of our own—feels like a portal through which you may pass into an enchanted kingdom,” Monbiot says. “The story rewilding tells us is that ecological change need not always proceed in one direction. It offers us the hope that our silent spring could be replaced by a raucous summer.”

Below, a few experiments in rewilding, drawn from Monbiot’s talk and elsewhere.

Bringing wolves back to Yellowstone National Park, Wyoming
Yellowstone National Park had become overrun with deer, which grazed away the vegetation dramatically. For years, biologists like Dave Foreman suggested a solution: bringing wolves back to the park, as the last ones were killed off in 1926. In 1995, wolves were finally reintroduced to Yellowstone, and the effects were dramatic. The wolves brought the deer population down to a sustainable population — but more importantly, they radically changed the behavior of the remaining deer. These deer started to move more often and avoid places in the park where they could easily be trapped, which in turn grew thick with vegetation. This allowed birds and beavers to move in, and the beavers’ dams became habitats for otters, muskrats, ducks, fish, reptiles and amphibians. The wolves also killed coyotes, which allowed for more rabbits and mice, which in turn boosted the populations of weasels, hawks, foxes and badgers. Meanwhile, ravens, bald eagles and bears fed on the carrion that the wolves left. In fact, even the river patterns in the park changed: the regenerating vegetation stabilized the riverbanks, which yielded less to erosion and took on straighter water flow. “The wolves, small in number, transformed not just the ecosystem of Yellowstone National Park—this huge area of land—but also its physical geography,” Monbiot explains in his talk..

Saving whales in the southern oceans
As a second example, Monbiot describes an unexpected way in which whales are a lynchpin of the ocean ecosystem — through their excrement. Whales feed at great depth, but come up near the water’s surface as they produce large fecal plumes. Up there, sunlight allows photosynthesis to take place, which results in the growth of phytoplankton. Zooplankton, which feed on phytoplankton, prosper in turn; and they feed fish and krill—which feed whales. Not only that, but whales’ movements push phytoplankton—which absorbs carbon—back up toward the water’s surface, where it can continue to survive and reproduce. According to Monbiot, at their usual historic populations, whales were probably responsible for sequestering tens of millions of tons of carbon from the atmosphere every year. So the management of whaling, and whale conservation by groups like the International Whaling Commission is, in this sense, a form of rewilding..

Restoring trees in Glen Moriston, ScotlandDundreggan, a 10,000-acre estate in the Scottish Highlands, is currently overgrazed by deer and sheep, which have decimated the local vegetation. In an ongoing, decades-long process, the organization Trees for Life is reforesting the area. “Our vision is to turn Dundreggan into one of Scotland’s finest native woodlands, abundant in wildlife, and protected for generations to come,” the website reads. The organization’s long-term goal is to restore the native forest of oak, hazel, ash and Scots pines to over half of the land. By 2058, they expect to see animals like the red squirrel, European beaver and wild boars return to the area..

Bringing beavers to mid Wales
The Cambrian Wildwood, a Wales Wild Land Foundation project, aims to restore Blaeneinion, 75 acres of land in mid Wales. The initiative, which launched in 2008, is reforesting the area with broadleaf trees, creating orchards. They are also introducing beavers to the area. “Alongside the reforestation of roughly 50 acres of pastureland, the project will incorporate subsistence organic food-growing, beekeeping, rearing small livestock and poultry, propagation of productive local fruit varieties, mushroom production, teaching components, social events, aquaculture and much, much more,” the website promises..

A jaguar reserve in Sonora, Mexico
It sounds strange, but it’s true — jaguars were once a fixture of the southern United States and northern Mexico. The Northern Jaguar Project works to restore habitats for jaguars and other threatened and endangered species in the area. Currently, an estimated 80-120 jaguars inhabit their Northern Jaguar Reserve in northeastern Sonora, which was established in 2003. In 2008, the reserve raised funds to purchase more land and the reserve is now a stunning 35,000-acre ranch where jaguars roam undisturbed..

Revegetating the White River National Forest. Colorado
The White River National Forest is a 2.3 million acre park in the Rocky Mountains. The Wilderness Workshop, founded in 1967, aims to keep large swaths of it truly wild — free of roads that fragment wilderness, free of human crowds that can disrupt animals and free of logging, mining and gas drilling which can harm the ecosystem. While much of their work is about defending the wilderness as it stands, their Habitat Restoration Program is about peeling back the effects of past damage and letting the land heal itself. The Program’s projects work on erosion control, weed removal, revegetation and, of course, reintroduction of native plant and animal species..

Bringing trout to South London
In 1805, the River Wandle was described as “the hardest worked river for its size in the world.” Ninety mills used the river then and, until very recently, it was routinely mowed of natural features to keep its water moving quickly. The last trout was caught in the river, which joins with the Thames, in 1934. In this article, Monbiot describes The Wandle Trust, which aims to restore the river by cleaning it out, redirecting its flow and restocking it with fish. Now, shrimp, insects and trout flourish in the river … even in proximity to the big city. “Astonishingly in view of where it has come from—historically and geographically—it looks in places like the kind of chalkstreams you would expect to find flowing through some of the most bucolic landscapes in England,” writes Monbiot.

Greg Asner closes Session 2 of TEDGlobal 2013, “Those Flying Things,” with a very different vision of the Earth. We spend a lot of time, money and resources conserving nature, yet, as Asner points out, we know absurdly little about it. Which is why, in an effort to advance our knowledge about biodiversity, he founded the Carnegie Airborne Observatory (CAO). The CAO uses laser scanning systems and two imaging spectrometers to image the Earth in 3D, capturing landscapes in extremely sharp chemical and biological detail. The CAO, in essence, captures the building blocks of ecosystems.

Asner asks and answers three questions about his work:

1. How do we manage our carbon reserves in tropical forests?

Tropical forests contain vast amounts of carbon stocks, and they need to stay there to prevent global warming from getting worse. Carbon emission levels from deforestation are now so high that emissions equal all the carbon emissions from the global transportation sector. The challenge for governments is targeting exactly where the carbon is in all these forests. In this case, CAO basically serves as a very high-tech accounting system, cutting the forests into millions of slices, mapping landscapes by the density of its carbon stocks.

2. How do we prepare for change in a place like the Amazon rainforest?

The Amazon was so dry in 2010 that the main stem of the Amazon River itself dried up, to devastating effect. CAO imaging was able to reveal that the droughts were causing widespread damage in remote areas, and that climate change seemed to be forcing species to migrate across vast distances. In addition, CAO allowed Asner and his team to digitally remove the forest, exposing clandestine gold miners.

3. How do we manage biodiversity on the planet and help the ecosystem?

With so many species under protection, park managers are under duress to manage systems in ways that can support multiple species. Fires and elephants alike can take their toll on parks and have detrimental cascading effects for many species. How can they be managed? In response Asner and his team are mapping every tree in the Savanna, then seeing which trees have been pushed over by animals. This allows park managers to make better decisions and pinpoint where species need the most help.

At TEDGlobal 2013 environmental systems researcher Lian Pin Koh presents a new and unexpectedly benign use for drones: nature conservation.

Nepal has natural landscapes that are beautiful — and in danger. But wildlife conservation is costly, and time- and labor-consuming. Behold: Conservation drones, a new tool being used in Nepal to combat wildlife crime. These drones give a bird’s-eye view of the landscape and capture detailed, high-definition images of objects on the ground.

Conservation drones are cheap and simply made. At the core, they are model aircrafts fitted with autopilot systems. Each contains a small computer chip equipped with a GPS, barometric altimeter and other sensors, and carries a payload such as a video or photographic camera. The software allows a user to program the drone easily on an open-source Google Maps interface, and the drone even lands itself. All told, one drone costs no more than a decent laptop.

Koh’s drones are now used in remote parts of the Indonesian rainforest to track orangutan nests and monitor the species population. Traditionally, orangutan monitoring happens on foot with binoculars, and in the past it has cost up to a quarter of a million dollars to estimate the size of the population in this region.

Koh and his team have been able to capture dozens of nests on camera, and are working with scientists now to develop algorithms that could automatically detect orangutan nests from among thousands of photos.

Recently Koh and his team have begun experimenting with thermal imaging cameras to detect poachers. And conservation drones are rapidly improving; Koh’s latest MAJA model has a 1.8-meter wingspan, weighs two kilograms, and can stay in the air 40 to 60 minutes at a time. The potential uses are endless: They can be used to monitor other species populations, the health of trees, deforestation, agricultural expansion, illegal logging, and so on. As Koh and his team are showing, drones are not only the ultimate “toys for boys,” but can be effective tools in protecting the environment.

Writer and political activist George Monbiot (with only three days’ notice, says Bruno!) joins Session 1: “Moments of Truth.” As a young man, Monbiot went off on adventures in the wild as an investigative ecology journalist. When he returned after six years to his life in Britain, he found himself inundated with the mundane, scratching at the walls of his life. He was ecologically bored.

Monbiot had almost accepted his fate as banal Briton when he discovered rewilding, a conservation movement that has come to popularity in the past two decades, and which drastically shifted Monbiot’s perspective of ecological boredom. One of the primary goals of rewilding is the mass restoration of ecosystems, and one way in which that can happen is trophic cascading, in which animals at the top of the food chain affect processes all the way down the food chain.

Monbiot’s gives a classic example: In 1995, wolves were reintroduced into Yellowstone National Park, 70 years after they had been exterminated. Wolves take life, but they also giveth. An unfathomable cascade followed: Deer populations went down, so streamsides and riversides flourished again; trees on the riverbanks quadrupled in height in just six years; bare valleys reverted to aspen and willow; birds and beavers alike flourished; beavers’ dams created habitats for otters, muskrats, fish, frogs and reptiles; and on and on.

And a glorious, unexpected side effect: The wolves altered the rivers themselves. The return of trees reduced the rate of erosion and narrowed the width of the streams, meanwhile creating a greater diversity of pools and riffles. Even on the hillsides, vegetation has begun to recover. The Yellowstone wolves demonstrated that a single species, when allowed to pursue its natural behavior, can transform an entire ecosystem.

Consider the example of whales in the southern oceans. Though the Japanese government has argued that whaling boosts the population of krill and fish, the opposite appears to be true. Declining numbers of whales have an adverse ripple effect on the ocean’s ecosystem. Whales produce an iron-rich manure — “fecal blooms,” as scientists call them — that fertilizes plant plankton; more plant plankton means more zooplankton; more plankton means more food for fish and krill. And, Monbiot suggests, just as wolves have altered the behavior of the Yellowstone rivers, more whales could have changed the composition of the atmosphere for the better, since the plankton fertilized by them absorb carbon and remove it from the atmosphere. It would seem, says Monbiot, there is more and more evidence to support the Gaia hypothesis — that the Earth functions as a coherent and self-regulating system — from an ecological perspective.

Photo: James Duncan Davidson

But what are the limits to rewilding? In Monbiot’s view, it’s not about controlling nature but letting it find its own way. There are a few necessary actions, like reintroducing absent plants and animals and pulling down fences, but in his view rewilding is not a teleological progression, with a correct endpoint or ideal ecosystem. “It lets nature decide,” he says.

But according to Monbiot, the benefits of rewilding are beyond just ecological. Human life itself should be rewilded. This entails not the de-civilizing of modern life, nor the shedding or regression of technology, but a reintroduction of adventure and surprise back into everyday life. Why only focus on wolves, bears, lynx, bison, moose and beaver, all of which are spreading rapidly across Europe already? What about megafauna? Elephant-adapted trees? Lions in Trafalgar Square? “Why shouldn’t all of us have a Serengeti on our doorsteps?” he asks, to laughs and applause.

Monbiot cites moments from his experience — seeing an osprey return to a local estuary for the first time in 400 years, making eye contact with a dolphin as it leapt over his kayak — as awe-inspiring, reintroducing him to “that high, wild note of exaltation after a drought of sensation that had persisted since early adulthood,” a drought he had previously accepted as an inevitable matter of growing up. But the world is much more interesting, surprising and complex than it seems, and drudgery doesn’t have to be our only experience. Rewild, says Monbiot, and “our silent spring could be replaced by a raucous summer.”

Sebastião Salgado has worked as a professional photographer since 1973. And he arrives on the TED stage with extraordinary gentleness and humility. He doesn’t think everyone is necessarily familiar with his work, so he starts by showing some of his incredible pictures, and we watch in silence. The images make for powerful, often difficult viewing. It’s clear that Salgado has traveled the world and shot the stories of so many people who are not regularly given a face. The pictures seem other-worldly; so beautifully staged and shot that it’s difficult to remember that this is real; this is photojournalism.

He starts by telling us some of his story, of being born on a farm in Brazil in 1944. It was a paradise, he says, of more than 50% rain forest that supported some 35 families. They ate everything they produced and were almost entirely self-sufficient. He left the farm when he was 15 years old, to move to the big city to start secondary school and another life, learning about politics and radicalism, becoming a “leftist,” studying to become an economist and, most important, meeting his “best friend all my life long,” Lelia Wanick, later to become Lelia Wanick Salgado, his wife and his companion to this day.

Politics intervened. A rapidly industrializing Brazil became unstable and an untenable place in which to live, and so the Salgados moved to France. It was there that at the age of 30, Sebastião discovered photography, the discipline that was to become his passion, his life. “I lived totally inside photography, doing long term projects.” He shows the audience another series of pictures that are epic in scale. Again we watch, in silence.

In the 1990s, Salgado photographed Migrations, traveling around the world to document just some of the many millions of people who have been uprooted from their homes by poverty, wars and repression. He saw deaths by the thousand–and the work took its toll. He became physically ill himself. Yet when he went to see a doctor, he found out that he wasn’t sick at all. “He says ‘You are not sick. What happened was you saw much death, you are dying. You must stop. Stop!'” Salgado agreed. He returned to his home in Brazil–and to the farm on which he had grown up.

Photo: James Duncan Davidson

He began shooting the project, known as Genesis, back in 2004, shooting through to 2009. And while he may have focused on documenting nature, people and humanity are still central themes, as he photographed tribes and people who live far from the so-called advances of the modern world. He shows us some of these images too (below). The ethereal, otherworldly beauty of the black-and-white shots is again extraordinary.

The Antarctic Peninsula. 2005. Iceberg between Paulet Island and the South Shetland Islands on the Antarctic Channel. At sea level, earlier flotation levels are clearly visible where the ice has been polished by the ocean’s constant movement. High above, a shape resembling a castle tower has been carved by wind erosion and detached pieces of ice. Courtesy Taschen.

Salgado is here with a call to arms. We must rebuild our forests, he says, just as he has done on his family’s land in Brazil. The destruction of the rainforest, of redwood trees in California, is unacceptable. It is simply the only way to capture carbon, to create the oxygen the planet needs to survive and thrive. Salgado makes a comparison: if you have a lot of hair, it might take two or three hours to dry your hair. “Me?” he says drily, stroking his bald head. “One minute.” It’s a funny moment, but he’s making a serious point. “The trees are the hair of the planet,” he says.

Brazil. 2005. In the Upper Xingu region of Brazil’s Mato Grosso state, a group of Waura Indians fish in the Puilanga Lake near their village. The Upper Xingu Basin is home to an ethnically-diverse population, with the 2,500 inhabitants of 13 villages speaking languages with distinct Carib, Tupi and Arawak roots. While they occupy different territories and preserve their own cultural identities, they co-exist in peace. Courtesy Taschen.

The photographer concludes by showing some breathtaking before-and-after pictures of his farm in Brazil. We see the erosion, the dried soil, the arid landscape of the home to which he returned. And then we see a shot from two months ago, with the forest almost entirely retored. They haven’t managed to plant all the needed 2.5 million trees yet, but two million are planted, with the resulting sequestration 100,000 tons of carbon. It’s an uplifting end to a sobering talk.

An exhibition of 250 images from “Genesis” premieres at the Natural History Museum in London in April, before touring to Toronto, Rio de Janeiro, Rome, and Paris.